Lovro Šubelj

I am graphs & networks enthusiast @ University of Ljubljana
Faculty of Computer and Information Science
Faculty of Mathematics and Physics
Faculty of Social Sciences

Network Science

I am interested in structure and dynamics of complex networks. My research focuses on developing methods and algorithms for network abstraction, modeling, sampling and comparison, node clustering and partitioning, and node position and link analysis.

Graph Machine Learning

I am also interested in machine learning with graphs in general, and in graph representation learning and relational deep learning in particular.

General Data Science

My other fields of interest include selected areas of data analysis, data mining, stream mining and statistics.

Journal Papers

  1. Only author. ``Computing well-balanced spanning trees of unweighted networks''. e-print arXiv:2205.06628v3, 1-18 (2025).
  2. With Romi Koželj & Jurij Bajc. ``Methods for representing earthquake time series with networks''. Informatica 48(14), 1-26 (2024).
  3. With Milan Jović, Tea Golob, Matej Makarovič, Taha Yasseri, Danijela Boberić Krstićev, Srdjan Škrbić & Zoran Levnajić. ``Terrorist attacks sharpen the binary perception of ``Us'' vs. ``Them''''. Scientific Reports 13, 12451 (2023).
  4. With Vincent Traag. ``Large network community detection by fast label propagation''. Scientific Reports 13, 2701 (2023).
  5. With Ilya Makarov, Dmitry Kiselev & Nikita Nikitinsky. ``Survey on graph embeddings and their applications to machine learning problems on graphs''. PeerJ Computer Science 7, e357 (2021).
  6. With Ludo Waltman, Vincent Traag & Nees Jan van Eck. ``Intermediacy of publications''. Royal Society Open Science 7(1), 190207 (2020).
  7. With Luka Naglić. ``War pact model of shrinking networks''. PLoS ONE 14(10), e0223480 (2019).
  8. With Dalibor Fiala, Tadej Ciglarič & Luka Kronegger. ``Convexity in scientific collaboration networks''. Journal of Informetrics 13(1), 10-31 (2019).
  9. Only author. ``Convex skeletons of complex networks''. Journal of the Royal Society Interface 15(145), 20180422 (2018).
  10. With Tilen Marc. ``Convexity in complex networks''. Network Science 6(2), 176-203 (2018).
  11. With Neli Blagus & Marko Bajec. ``Empirical comparison of network sampling: How to choose the most appropriate method?''. Physica A 477, 136-148 (2017).
  12. With Dalibor Fiala. ``Publication boost in Web of Science journals and its effect on citation distributions''. JASIST 68(4), 1018-1023 (2017).
  13. With Nees Jan van Eck & Ludo Waltman. ``Clustering scientific publications based on citation relations: A systematic comparison of different methods''. PLoS ONE 11(4), e0154404 (2016).
  14. With Marko Bajec, Biljana M. Boshkoska, Andrej Kastrin & Zoran Levnajić. ``Quantifying the consistency of scientific databases''. PLoS ONE 10(5), e0127390 (2015).
  15. With Neli Blagus, Gregor Weiss & Marko Bajec. ``Sampling promotes community structure in social and information networks''. Physica A 432, 206-215 (2015).
  16. With Dalibor Fiala, Slavko Žitnik & Marko Bajec. ``Do PageRank-based author rankings outperform simple citation counts?''. Journal of Infometrics 9(2), 334-348 (2015).
  17. With Dalibor Fiala & Marko Bajec. ``Network-based statistical comparison of citation topology of bibliographic databases''. Scientific Reports 4, 6496 (2014).
  18. With Slavko Žitnik, Neli Blagus & Marko Bajec. ``Node mixing and group structure of complex software networks''. Advances in Complex Systems 17(7), 1450022 (2014).
  19. With Neli Blagus & Marko Bajec. ``Assessing the effectiveness of real-world network simplification''. Physica A 413, 134-146 (2014).
  20. With Slavko Žitnik & Marko Bajec. ``SkipCor: Skip-mention coreference resolution using linear-chain conditional random fields''. PLoS ONE 9(6), e100101 (2014).
  21. With Marko Bajec. ``Group detection in complex networks: An algorithm and comparison of the state of the art''. Physica A 397, 144-156 (2014).
  22. With Slavko Žitnik, Dejan Lavbič, Olegas Vasilecas & Marko Bajec. ``General context-aware data matching and merging framework''. Informatica 24(1), 119-152 (2013).
  23. With Dejan Lavbič, Slavko Žitnik, Aleš Kumer, Aljaž Zrnec & Marko Bajec. ``Traversal and relations discovery among business entities and people using semantic web technologies and trust management''. Databases and Information Systems 7, 164-174 (2013).
  24. With Marko Bajec. ``Ubiquitousness of link-density and link-pattern communities in real-world networks''. European Physical Journal B 85(1), 32 (2012).
  25. With Neli Blagus & Marko Bajec. ``Self-similar scaling of density in complex real-world networks''. Physica A 391(8), 2794-2802 (2012).
  26. With Marko Bajec. ``Robust network community detection using balanced propagation''. European Physical Journal B 81(3), 353-362 (2011).
  27. With Marko Bajec. ``Community structure of complex software systems: Analysis and applications''. Physica A 390(16), 2968-2975 (2011).
  28. With Marko Bajec. ``Unfolding communities in large complex networks: Combining defensive and offensive label propagation for core extraction''. Physical Review E 83(3), 036103 (2011).
  29. With Štefan Furlan & Marko Bajec. ``An expert system for detecting automobile insurance fraud using social network analysis''. Expert Systems with Applications 38(1), 1039-1052 (2011).
  30. With Bojan Klemenc, Peter Ciuha, Lovro Šubelj & Marko Bajec. ``Visual and aural: Visualization of harmony in music with colour''. IPSI BgD Transactions on Internet Research 7(1), 48-53 (2011).
  31. With David Jelenc, Eva Zupančič, Dejan Lavbič, Denis Trček, Marjan Krisper & Marko Bajec. ``Merging data sources based on semantics, contexts and trust''. IPSI BgD Transactions on Internet Research 7(1), 18-30 (2011).

Book Chapters

Conference Talks & Posters

  1. With Vid Stropnik. ``Predicting successful passes in football: Benchmark dataset and GNN ablation study''. In: Proceedings of the 20th International Conference on Network Science NetSci (Maastricht, Netherlands, 2025), p. 1.
  2. With Vincent Traag. ``Fast label propagation algorithm for community detection''. In: Proceedings of the 18th International Conference on Network Science NetSci (Vienna, Austria, 2023), p. 1.
  3. With Nejc Rožman, Marko Corn, Gašper Škulj & Janez Diaci. ``Emergence of a scale‐free network topology in a blockchain‐based shared manufacturing''. In: Proceedings of the 3rd International Conference on Blockchain Computing and Applications BCAA (Tartu, Estonia, 2021), pp. 172‐178.
  4. Only author. ``Spanning trees that preserve network distances''. In: Proceedings of the 1st Joint Sunbelt and NetSci Conference Networks (Washington, USA, 2021), pp. 270-271.
  5. With Luka Naglić. ``War pact network model: A generative model of networks that shrink''. In: Proceedings of the 4th European Social Networks Conference EUSN (Zurich, Switzerland, 2019), p. 240.
  6. With Ludo Waltman, Vincent Traag & Nees Jan van Eck. ``Intermediacy of publications''. In: Proceedings of the 17th International Conference on Informetrics and Scientometrics ISSI (Rome, Italy, 2019), pp. 1288-1300.
  7. With Ludo Waltman, Vincent Traag & Nees Jan van Eck. ``Intermediacy of publications''. In: Proceedings of the 5th International Conference on Computational Social Science IC2S2 (Amsterdam, Netherlands, 2019), pp. 1-3.
  8. With Ludo Waltman, Vincent Traag & Nees Jan van Eck. ``Uncovering important intermediate publications''. In: Proceedings of the 38th INSNA International Social Network Conference Sunbelt (Utrecht, Netherlands, 2018), p. 1.
  9. Only author. ``Convex skeleton: Generalization of a network spanning tree''. In: Proceedings of the 1st NetSci Workshop on Large and Rich Network Structures LaRichNet (Paris, France, 2018), p. 1.
  10. With Ludo Waltman, Vincent Traag & Nees Jan van Eck. ``Intermediacy of publications''. In: Proceedings of the 13th International Conference on Network Science NetSci (Paris, France, 2018), p. 1.
  11. With Tilen Marc. ``Three forms of convexity in graphs and networks''. In: Proceedings of the 2nd European Conference on Statistical Network Science COSTNET (Palma de Mallorca, Spain, 2017), p. 54.
  12. With Marko Mišić, Dražen Drašković & Marko Bajec. ``Parallel implementation of the label propagation method for community detection on the GPU''. In: Proceedings of the 26th International Electrotechnical and Computer Science Conference ERK (Portorož, Slovenia, 2017), pp. 359-362.
  13. With Tilen Marc. ``On convexity in complex networks''. In: Proceedings of the 8th International Conference on Complex Networks CompleNet (Dubrovnik, Croatia, 2017), pp. 14-16.
  14. With Nees Jan van Eck & Ludo Waltman. ``Comparison of methods for clustering citation networks''. In: Proceedings of the 2nd International Conference on Network Science X NetSci-X (Wroclaw, Poland, 2016), p. 1.
  15. Only author. ``Exploratory and predictive tasks of network community detection''. In: Proceedings of the 10th International Conference on Network Science NetSci (Zaragoza, Spain, 2015), p. 1.
  16. With Dalibor Fiala & Marko Bajec. ``Consistency of citation topology of bibliographic databases''. In: Proceedings of the 10th International Conference on Network Science NetSci (Zaragoza, Spain, 2015), p. 1.
  17. Only author. ``Large network community detection in practical scenarios''. In: Proceedings of the 5th International Workshop on Social Network Analysis ARS (Capri, Italy, 2015), p. 78.
  18. With Marko Bajec. ``Network group discovery by hierarchical label propagation''. In: Proceedings of the 1st European Social Networks Conference EUSN (Barcelona, Spain, 2014), p. 284.
  19. With Zoran Bosnić, Matjaž Kukar & Marko Bajec. ``Automatization of the stream mining process''. In: Proceedings of the 26th International Conference on Advanced Information Systems Engineering CAiSE (Thessaloniki, Greece, 2014), pp. 409–423.
  20. With Slavko Žitnik & Marko Bajec. ``Who reads and who cites? Unveiling author citation dynamics by modeling citation networks''. In: Proceedings of the 9th International Conference on Network Science NetSci (Berkeley, California, USA, 2014), p. 1.
  21. With Gregor Weiss, Neli Blagus & Marko Bajec. ``What coins the bitcoin? Exploratory analysis of bitcoin market value by network group discovery''. In: Proceedings of the 9th International Conference on Network Science NetSci (Berkeley, California, USA, 2014), p. 1.
  22. With Neli Blagus, Gregor Weiss & Marko Bajec. ``Large networks grow smaller: How to choose the right simplification method''. In: Proceedings of the 9th International Conference on Network Science NetSci (Berkeley, California, USA, 2014), p. 1.
  23. With Slavko Žitnik, Marko Janković, Bojan Furlan, Dražen Drašković, Nemanja Kojić, Marko Mišić & Marko Bajec. ``Iterative end-to-end information extraction based on linear models''. In: Proceedings of the 22nd International Electrotechnical and Computer Science Conference ERK (Portorož, Slovenia, 2013), pp. 47–50.
  24. With Miloš Pavković, Dražen Drašković, Slavko Žitnik, Dejan Lavbič, Marko Janković, Jelica Protić & Boško Nikolić. ``Intelligent techniques for searching internet forums''. In: Proceedings of the 22nd International Electrotechnical and Computer Science Conference ERK (Portorož, Slovenia, 2013), pp. 85–88.
  25. With Neli Blagus & Marko Bajec. ``Group extraction for real-world networks: The case of communities, modules, and hubs and spokes''. In: Proceedings of the 8th International Conference on Network Science NetSci (Copenhagen, Denmark, 2013), pp. 152–153.
  26. With Neli Blagus & Marko Bajec. ``Preserving properties under simplification of real‐world networks''. In: Proceedings of the 8th International Conference on Network Science NetSci (Copenhagen, Denmark, 2013), p. 166.
  27. With Marko Bajec. ``Model of complex networks based on citation dynamics''. In: Proceedings of the 2nd WWW Workshop on Large Scale Network Analysis LSNA (Rio de Janeiro, Brazil, 2013), pp. 527–530.
  28. With Slavko Žitnik, Dejan Lavbič, Aljaž Zrnec & Marko Bajec. ``Collective information extraction using first-order probabilistic models''. In: Proceedings of the 5th Balkan Conference in Informatics BCI (Novi Sad, Serbia, 2012), pp. 279–282.
  29. With Marko Bajec. ``Software systems through complex networks science: Review, analysis and applications''. In: Proceedings of the 1st KDD Workshop on Software Mining SoftMine (Beijing, China, 2012), pp. 9–16.
  30. With Dejan Lavbič, Slavko Žitnik, Aleš Kumer, Aljaž Zrnec & Marko Bajec. ``Traversal and relations discovery among business entities and people using semantic web technologies and trust management''. In: Proceedings of the 10th International Baltic Conference on Databases and Information Systems DB&IS (Vilnius, Lithuania, 2012), pp. 11.
  31. With Marko Bajec. ``Generalized network community detection''. In: Proceedings of the 1st ECML PKDD Workshop on Finding Patterns of Human Behaviors in Network and Mobility Data NEMO (Athens, Greece, 2011), pp. 66–84.
  32. With Marko Bajec. ``Unfolding network communities by combining defensive and offensive label propagation''. In: Proceedings of the 1st ECML PKDD Workshop on the Analysis of Complex Networks ACNE (Barcelona, Spain, 2010), pp. 87–104.
  33. With Bojan Klemenc, Peter Ciuha & Marko Bajec. ``Visual and aural: Visualization of harmony in music with colour''. In: Proceedings of the VIP Symposia on Internet Related Research VIPSI (Tivat, Montenegro, 2010), pp. 6.
  34. With David Jelenc, Eva Zupančič, Dejan Lavbič, Denis Trček, Marjan Krisper & Marko Bajec. ``Merging data sources based on semantics, contexts and trust''. In: Proceedings of the VIP Symposia on Internet Related Research VIPSI (Amalfi, Italy, 2010), pp. 13.

Invited Talks & Seminars

  1. ``Intermediacy and convexity in networks''. Department seminar (Márton Pósfai, Central European University, Department of Network and Data Science, 2025).
  2. ``Network abstraction with backbones and skeletons: Spanning trees versus convex skeletons''. Department seminar (Tim Evans, Imperial College London, Centre for Complexity Science, 2022).
  3. ``On computing spanning trees of unweighted networks''. Wednesday Seminar (Vladimir Batagelj, University of Ljubljana, Faculty of Mathematics and Physics, 2021).
  4. ``Intermediacy of publications: Uncovering important publications for the development of a field''. At: 6th European Conference on Statistical Network Science COSTNET (online, 2020).
  5. ``Label propagation for clustering''. At: 6th Slovenian Conference on Network Science NetSlo (Ljubljana, Slovenia, 2020).
  6. ``Intermediacy of publications''. At: 5th Slovenian Conference on Network Science NetSlo (Ljubljana, Slovenia, 2019).
  7. ``Intermediacy of publications''. AI Seminar (Marko Robnik-Šikonja, University of Ljubljana, Faculty of Computer and Information Science, 2019).
  8. ``Convexity in complex networks''. LCN2 Seminar (Frank W. Takes, Leiden University, Institute of Advanced Computer Science, 2017).
  9. ``Network analysis in bibliometrics''. Department seminar (Vincent Traag, Leiden University, Centre for Science and Technology Studies, 2017).
  10. ``On convexity in complex networks''. At: 6th International Workshop on Social Network Analysis ARS (Naples, Italy, 2017).
  11. ``Should you (not) publish in computer science journals?''. Cookie Seminar (Sebastijan Šprager, University of Ljubljana, Faculty of Computer and Information Science, 2017).
  12. ``Comparison of methods for clustering scientific publications based on citations''. IBMI Seminar (Nataša Kejžar, University of Ljubljana, Faculty of Medicine, 2017).
  13. ``Reliability of bibliographic databases for scientometrics network analysis''. At: 8th International Conference on Information Technologies and Information Society ITIS (Šmarješke toplice, Slovenia, 2016).
  14. ``On convexity in complex networks''. Wednesday Seminar (Vladimir Batagelj, University of Ljubljana, Faculty of Mathematics and Physics, 2016).
  15. ``Network analysis vs WikiLeaks''. Cookie Seminar (Janez Demšar, University of Ljubljana, Faculty of Computer and Information Science, 2015).
  16. ``Selected topics from network analysis''. Wednesday Seminar (Vladimir Batagelj, University of Ljubljana, Faculty of Mathematics and Physics, 2014).
  17. ``Network analysis''. Habilitation lecture (Igor Kononenko, University of Ljubljana, Faculty of Computer and Information Science, 2014).
  18. ``Network and link analysis''. Department seminar (Dalibor Fiala, University of West Bohemia, Department of Computer Science and Engineering, 2014).
  19. ``Detecting groups of nodes in networks by label propagation''. Invited lecture (Zoran Levnajić, Faculty of Information Studies in Novo mesto, 2014).
  20. ``An expert system for detecting automobile insurance fraud using social network analysis''. Invited talk (Slovenian Academy of Sciences and Arts, 2013).
  21. ``Detecting insurance fraud using network analysis''. Seminar for Probability, Statistics and Financial Mathematics (Aleš Toman, University of Ljubljana, Faculty of Mathematics and Physics, 2013).
  22. ``Structured-world conjecture: On modules and communities in real-world networks''. Group seminar (Jure Leskovec, Stanford University, Computer Science Department, 2012).
  23. ``Structured-world conjecture: On modules and communities in real-world networks''. AI Seminar (Charles Elkan, University of California, San Diego, Department of Computer Science and Engineering, 2012).
  24. ``Introduction to data networks analysis''. Invited lecture (Marko Bajec, University of Ljubljana, Faculty of Computer and Information Science, 2010).

Patents & Applications

  1. With Marko Bajec. ``The process for allocation of computational resources in networks of distributed devices''. Slovenian Institute of Intellectual Property SI-24553-A (Ljubljana, Slovenia, 2015), P-201300392, pp. 5.
  2. With Slavko Žitnik, Dejan Lavbič, Aleš Kumer & Marko Bajec. ``Combining heterogeneous data sources of data processing devices''. Slovenian Institute of Intellectual Property (Ljubljana, Slovenia, 2013), P-201300263, pp. 7.

For complete list of publications see my CV.

Teaching

I teach BSc, MSc, and PhD courses in network science and analysis, machine learning with graphs, Python and Java programming, and databases and information systems. Some of my lectures are available on YouTube.

Data & Code

Many of the networks I have compiled are available through Netzschleuder, ICON and the Network Repository. For code see repositories netpy-workshop, node-intermediacy, graph-convexity, convex-skeleton, nets-nodegroups, etc.

Feel free to contact me, especially if you are interested in network science or machine learning with graphs.

lovro.subelj@fri.uni-lj.si